"The attackers on 9/11 never stood a chance against the American people — and outsiders who wish us harm never will," Lieberman wrote for The Hill. "But we have the capacity to destroy our democracy ourselves. Civility is the foundation of a productive democracy."

However, "civility seems to have left our national government," allowing polarization to fester and basic work of the Congress to be stifled, Lieberman writes.

No one will remember where they were when the government shut down, but that was another symptom that doesn't bode well.

"Today, we confront a more tempestuous political environment. The basic rhythms of the national legislative process — the norms that prompted Republicans and Democrats to work together in the service of the greater good — are gone," Lieberman wrote. "Our democracy is proving unable to meet the challenges of the moment. We face real trouble ahead."

What does it say when neither Democrats or Republicans can make it through a State of the Union address without a rude outburst or showing basic respect?

"If Democrats and Republicans can't even bear to listen to a president of the other party present his agenda in the temple of our democracy, how can we expect them to collaborate respectfully and productively when trying to find solutions to our most difficult problems?" Lieberman writes.

Lieberman cited Abraham Lincoln's words that should serve as a warning:

"If destruction be our lot, we must ourselves be its author and finisher. As a nation of freemen, we must live through all time, or die by suicide."